Getting started with python

When first started with python I noted some patterns that seem to have python and javascript although their syntaxis is quite not the same, you can relate writing python with javascript as a way to learn it way more efficiently. We will be creating a small terminal app so you can learn the basics of python

Goals:

• Learn how to create variables
• Define functions
• Use While and For loops
• Get input from the user using the terminal
• Understand range() method
• Interpolation
• Use if/else statements

Requirements:

• Python -v 3.7.4
• Code editor - I'll be using VSCode
• Terminal

Acknowledgments:

I'm a beginner in python so I'm just sharing what I recently learned. In this tutorial, I use a lot of escape characters in case you don't know what they are or you need to remember them:

Go ahead and open your editor of choice and without further, let's start!

We will imagine that we work at a coffee shop and several clients approach us at the same time, and they all want a cup of coffee so we as software developers need to configure out a bot to prepare them as soon as possible because making it ourselves would take much time, and configure it so it can remember each client name for they feel well attended :)

Create a python file and call it as you wish. I'll call it coffeePrepBot.py. We will need to:

• Create a variable for storing clients name's
• Have a way to know (like a Boolean) when we finished all the requests
• Make the bot to ask each client for the type of coffee they want and give them the coffee

coffee_count = 0
is_done = False
clients = []

After you created these three variables in the next line copy/paste:

def get_client_name():
  return input('How\'s the client name? ')

What we did up there was to define a function that returns the name that the client gives up to make up his/her coffee. The input(string) method receives a text string for context about what we want.

def coffee_clients_listing():
    for coffees in range(0, coffee_count):
      clients.append(get_client_name())

After defining the coffee_clients_listing() function, we notice something new: range()

What the range() function does?

The range() function returns a series of numbers making it an iterable, and it has two sets of parameters, as follows: range([start], stop[, step])

• start: Starting number of the sequence.
• stop: Generate numbers up to, but not including this number.
• step: Difference between each number in the sequence.

Example:

Let's say we want to print to the console the numbers from 1 to 5. We create the following variable

range_numbers = range(1, 6) # number 6 not included

If we do print(range_numbers) we get: range(1, 6) but if we use a for loop like so:

range_numbers = range(1, 6) # number 6 not included
for num in range_numbers:
  print(num)

# We get
-> 1
-> 2
-> 3
-> 4
-> 5

Ok, let's keep going. We were defining coffee_clients_listing():

def coffee_clients_listing():
    for coffees in range(0, coffee_count):
      clients.append(get_client_name())

What coffee_clients_listing() does is that it receives coffee_count which is the number of coffees we need to make, and add to the list (or array as you prefer to call them) the name of the client, calling the get_client_name() function.

In the next line copy/paste the following:

while not is_coffees_done:
  coffee_count = int(input('[BOT]: How many coffee\'s you need to make? '))

  print('\n[BOT]: Bip Bop Bup... Okay! we will create a list \nwith the name of the clients who asked for a coffee \nso we can start preparing them wink wink\n')
  coffee_clients_listing()

  print('\nWe have the list with all the clients who asked for coffee: ', clients)

  for client in clients:
    coffee = input(f'\n[BOT]: Hi {client}, we have \n- Expresso\n- Capuchino\n- Late\n-and American \nWhat type of coffee you want? ')
    print(f'\n[BOT]: Coming out a {coffee} for: {client} :) \n')

  is_coffees_done = input('[BOT]: You need to make more coffees? ')
  if is_coffees_done.lower() == 'yes': is_coffees_done = False
  else: is_coffees_done = True

print('That\'s all for me. Call me again when you need me :] bip bup shutting down...')

What we just did:

• We defined a while loop that will run over and over until the variable is_coffees_done becomes True.

• We're asking each client for their name and saluting then when giving them their coffee back

Interpolation it's done with the f property inside the print function. It's a feature of Python v3 print(f'String {variable} whatever follows...') You can learn more at the useful resources section.

The last three lines are important because if not the bot would make coffees infinitely, we're saying: hey! ask your supervisor (or whatever) I'm done? or there are more coffees to serve? If yes, we start from the top of the while loop and if not the bot shuts down itself

That's all for now folks! :)

Conclusion

We learned that in python:

• Variables follow the pattern: variable_name = value
• Functions are declared with : def myFunction()
• Briefly that comments can be made with #
• We can add items to a list(or array) with the method .append()
• How to declare while loops and exit them
• Use if/else statements

Useful resources:

• https://www.w3schools.com/python/python_ref_keywords.asp
• https://www.w3schools.com/python/exercise.asp
• https://www.w3schools.com/python/python_quiz.asp
• https://www.programiz.com/python-programming/string-interpolation
• https://www.youtube.com/playlist?list=PLlrxD0HtieHhS8VzuMCfQD4uJ9yne1mE6